There are many simples, for example, and those even of great power and ac tivity, in which we can distinguish no pre dominant sensible quality ; there are many, again, in which various qualities are so equally united, that they have just the same claim to a position under one class or order as under another ; and there are many, also, which, though simi lar in their sensible qualities, are very dissimilar in their effects upon the ani mal frame : thus, though gentian and aloes agree in possessing a bitter taste, and sugar and manna in being sweet, their medical virtues are widely different. Accordingly, Cartheuser himself is com pelled to deviate ocasionally from his general plan, and to found a part of his division on the medicinal effects of his materials ; introducing not only a class of ,purgatives and emetics, but of vaporose inebriants and narcotics ; under which last class be arranges tobacco, elder-flow er, saffron, opium, and poppy.seeds, sub stances, certainly, very discordant in all the qualities that relate to medicinal in tentions.
The last division we shall notice is that of Vogel, who has classified his materials according to their effects on the human body. Some are found to have the pro perty of rendering the solid parts of the frame more lax than before, and are hence denominated relaxing medicines ; others possess a directly contrary power, and are consequently called indurating medicines. A third kind are found to excite inflam mation in the part to which they are ap plied; and are therefore named inflam matory; while a fourth, from being per ceived to increase or diminish the vigour of the body, or what is called the tone of the solids, have acquired the name of tonics in the first instance, and sedatives in the second. Some, again, are conjec tured neither remarkably to increase nor diminish the tone of the solids ; but to perform their office either by correcting some morbid matter in the body, or by evacuating it ; in the former case they are called alterants, in the latter evacu ants.
These are the general divisions or clas ses into which simple medicines are par titioned under this system ; but when we begin to consider their virtues more par ticularly, a variety of inferior divisions must necessarily ensue. Thus, of the re laxing medicines, some, when externally applied, are supposed merely to soften the part ; and in such case are called emollients ; while others, which are sup posed to have a power of augmenting the disposition of the secernents of an in flamed part to the secretion of pus, are called maturants or suppuratives. Se dative medicines, that have the power of assuaging pain, are denominated parego rics ; if they altogether remove or de stroy pain, they are called anodynes ; if they take off spasm, antispasmodics ; if they produce quiet sleep, hypnotics ; if a very deep and unnatural sleep, to gether with considerable stupefaction of the senses, narcotics. Tonic medicines,
in like manner, obtain the name of corro boratives, analeptics, or nervines, when they slightly increase the contractile power of the solids ; but of astringents, or adstringents, if they do this in a great degree. Some of this order of medicines have been supposed to promote the growth of flesh, to consolidate wounds, and restrain hxmorrhages, and hence the mimes of narcotics and traumatics, or vuf neraries ; names, however, which may well be dispensed with, as the quality is very questionable, and perhaps altogether erroneously ascribed. Other astringents, „again, are denominated repellent, discu tient, stimulant, or attractive, according to the respective modes by which they are conceived to produce one common effect. Medicines of the inflammatory tribe, are, in like manner, divided into vesicatories or blisters, if by their appli cation they raise watery bladders on the skin ; cathicretics, escharotics or corro sives, if they eat into and destroy the sub stance of the solid parts themselves ; and rubefactive or rubefacient, if possessed of less power than the vesicatories, they merely produce a redness on the part to which they are applied, by increasing the action of a part, and stimulating the red particles of the blood into vessels which do not naturally possess them. The al terant tribe is divided into absorbents, antiseptics, coagulants, resolvents, cale fiants, and refrigerants, according to the peculiar mode by which the different in dividuals of this tribe are supposed to operate. The evacuants are generally subdivided from the nature of the hu mour they are supposed to discharge: emetics, if they evacuate the contents of the stomach by vomiting ; cathartics, if they induce purging ; laxatives, if they produce a moderate discharge of feces . pain or sickness ; eccoprotics, if the discharge be greater, but still con - fined to the common nature of the feces themselves. Thus again they are named diaphoretics, if they promote the expul sion of humours through the pores ofthe skin with it small increase of action ; su dorifics, if the increase of action he great er, and the discharge more copious. Such as excite urine are called diuretics ; such as produce evacuation from the glands of the palate, mouth, and salivary ducts, salivating medicines ; those that promote the discharge of mucus from the throat, apophiegmatics ; those that evacuate by the nose, ptarmics ; errhines, sternutatories ; and those which promote the menstrual discharge, emenagogues. To this order, also, some writers reduce those medicines which expel any preter natural bodies, as worms, stones, and fla tus or confined air : of these the first are called anthelmintics ; the second, and es pecially when directed to the bladder, lithontriptics; and the third, carminatives.